Underreamer.



T. J. GRIFFIN.

UNDERREAMER.

APPLIQATION FILED M111, 1912 Patented Mar. 16, 1915.

ZSHEETSSHBBT L ..1 1 111.119.1111. un H1+1|l11 1 1 1 1 1 L 21 mi f T. J. GRIFFIN.

UNDEBREAMER.

APPLICATION FILED APR. I, m12

Patented Mar. 16, 1915,

2 SHEHT'SY SHEET 2.

'lll/Ida J. GRIFFIN, OF LOS ANGELES, C LL'FRN'IA, Al*

EDWARD DOUBLE, OF LOS ANGELES, GA?- NOR OF' QNX-HALF TO j fill-NIA.

DERREAMR.,

Speoisation of Letters Patent.

Pa tent-ed Mar. 16. 1 91 5.

Application Bled April 1, 1912. Serial No. 6333MB.

To all 'whom` il may concern Be it known that l, THoMAs J. thorns, a citizen of tlie `United Patate-s ol' America., residing at lit-1 Singel( in the County of Los Angeles, State of @an ornia, bare invented a certain new and Improved llnderreamer, of which the following is a specification.

This invention relates to iinderroamers for reaming not or enlarging the well hole below tia easing in tile drilling oi. oil or Artesian Wells.

Among tbe objects of the invention is the provision of tin: collapsing bits or cnt-- ters in snel; torn. and so related to the body portion or in; el to positively obviate the possibility the accidental separation of the bits or entiers from tbe body of the tool and the emisequent loss of either one or both of the cutters or bits in the Well hole.

Other objects sought and accomplished by the invention will appear from a consideration ol' tlm embodiment oil' the inyenn tion shown in tite drawings and hereinafter described in detail.

Tile invention consists in the combinations of parte hereinafter described and `particularly set forth in the olaims and the. invention will be more readily undeistood by reference to the accompanying drawings illustrating the embodiment of tlieyinvention and in vs'bi Figure i. is a side elevation of" an underreamer embodying my invention. .i portion o f the upper end of the same being broken away, the cutters or bits being shown in open or distended position, the positions'of the internal parts being indicated in this view in dotted lines. Fig. 2 is a front elevation, the bits being shownfin open position and internal portions shown in dotted lines. Fig, 3 an inverted plan View of the underreamer with the bits or cutters in the position of Fig. l. Fig. 4 is a sectional plan View on the line @4mof Fig. 1. Fig. 5 is a longitudinal*sectional View of the under reamer, showing the positions the parts occupy when the. bits or cutters are in open or expanded position, the underre fr being shown as Y having just passed of the lower end of a Well oasing.f\. Eig. G is a longitudinal sectional vient of an underreanier embodying my invention, the same beingshown with the cutters or bits projecting from the lower end of the Well cas- 'position to be moved ing 'out stili in olosedor contracted posi tion, and illustrate:` the gxsition that tbe parts occupy reinen Lili-e `Vmflerreamer is in gli tlf"` nell oas ing. l. i' is a iol-gi mi sta ...not new illustrL 4ing tbe manner of removing rlie bits from the mandrel or body. Fig. is a lon gitndinal sectional. View of the mandrel or body portion. the movable pf all being omitted. Fig. 9 is a iront ia oi iin body or mandrel portion, the ble parts all being omitted. Fig. l ide iiew, and Fig. il. a face View i Elie critters or bits. Fig. 1&2 is a Aot' the, bit or cutter interlocking ke'. l) is an end View thereof. Fig. l-l fe. rien* of tie preferred form of spror which l may :n'iploy for reino\ f nnsion of tbe coil spring and tors in the cutters or bits and their r-z.. in order to permit the Withdrawal 4 removal of the nl or mand and spot-tively are fr." Y channel in bien .f

vln tlie embodiment i in the drawings .fein t, ms tile body or mandrel and 3 tbe bits i cutters respectively. The bits or cutters are mounted upon a spring-actuated" rod l being connected to this rod 4 by n key l5. The central portion of the mandrel if* body is bellow, the bore being of tWo diff( `ent diameters. As viewed from the Upper portion oi tin: mandrel. the bore is of large diameter for a sufficient distance to properly house and provide for the expansion of a coiled spring G surrounding tbe rod Al. In tbe lower pot'iion of the body this central bore is only s iglitly larger in diameter than the diameter `of the rod 4 and extends well toward tizio ltr-:rer end or bottom of the mandrel body tlnis forming a shoulder 7 against which one end of the t'oiled spring rests. the rod 4 being provided at. its upper end 'with a suitable Washer 8 and retainirg nut 9. The Washer and nut may be made seperate or in one piece and may be keyed n position on the rod if desired. Preferably the rod I4 is threaded at its upper end for sullicientdistance to provide for a suitable range of adjustment so as to provide for the desired spring tension of the coiled spring 6 when t. amor operates.

invention shown 1n position.

The lower portion ot"l the mandrel or body SND "is sh win there being a. siot ci" the lower portion of the '.ivct providing u central bnr This central portion ll s istered the key l5 may be readily withdran n front the rod l and through one side of the .key @ray The under side of the L nfwilielizY with n central concave lli mln; nl to engage the convex seat the roti l.

,is shown oestin Figa il, the side walls of the lower slcttcd portion of the body or n'ninil il provided :it the upper end with tvo concave seals 17 and with corre. ondiixg ways lS; lil lending respectivel ownwustl from sind shits :ind outward rom the 55de of the body nl the lower end of the wel 39.

@l n the lower ond oi the cent-ral port-lori l? and projecting ffnztwnrd through the side slr-'s if? arr two downwardly inclined abutments l? the lower of which are also inclined downwnrl'l and outward from the centr-il portion il, lt is obvious that these ummm-:nts 2l may ne formed as an integral part of the central portion or bar 11 or may be downwardly inclined lugs inserted in the slots ln the side walls und held therein bv pins or any other preferred device.

The upper ends of the Shanks 22 of the bits or cutters are provided with rounded parlions 53 corresponding in size withthe comme smits l? :mel indented to fit therein, the :runnin-l {wf-'time 2S ci the bits being extended sidewnw beyond the Shanks 22, thus forming lugs which work in the slots lt l) of the bodyS inclined shoulders 24 beng provided at the upper ends of the bits to engage tho inclined nbntments 25 of the iw y ien, the bits nro in expended posia-'rovidiug 'for the ends of the bits :le ng .on the body: and the inclination of tlm :i imams ilo being upward and inrnrll from the surface of the body tends t0 nlfl the bits: in fnl-ace, and upon the striking m n lili-:iw in drilling the tendency of the bits drive inward of the mandrel,or body n thais taking the :shock of the blow the strongest portions of the mandrel find y1 The lower ends of the bits are wider n tho shrinks 22 providing' the shoulders which are inclined upwardly and in wnrdly to correspond with the iurlin Non of the lower end of the mnnfilrel or nml portion against which the respective shfmlders Qt? abut when in expended position, The lower end of the mandrel or body portion from the center is inclined upwardly and :All

outwardly, as shown for two purposes, firsti to co-act with the shoulders 26 to canse the bits to be projected outward when drawn up by the tension of the spring 6, and secornh to form an abutment for the shoulders 2li, thereby taking n port-ion of the impact o the blow directly upon the end of the body, Each of the bits is provided with n recess 27 so that the bits may tit over the nijntnients 2l, the recess 27 being of greater width than the nbutments so that the bits may move thereon. The lower wall or surface of the recess 27 is inclined to correspond with the under surface of the :ibutxnent 21 so asto conticty therewith when the bits are .in expanded position,y thus bracing the bits against any tendency of the impact vto rip the. bits out sidewise of the body, and

the inclination of the abutments being n ward and A' ward from their outer ende S5 tends Vto furl ercounteract such n ction.

The sh'anlls 22 of the bits or cutters are provided with recesses 280i suliicient width to permit the insertion and withdrawal of the interlocking key 15 and are preferably provided with concave seats in which the convex lugs 29 on the key l5 engage. Pref erably one of the cutters or bits only the recess 28 o ening entirely through 'from side to side, tle recess in the other lming closed by an imperforate outer wall it only being neeessgry for one of the recesses to be open through the outer side of one bit to ectuate the insertion and withdrawal rey.

of the interlockin I may, if desire provide means for hold ing the spring-actuated rod 4 downward against the action of the spring 6 to permit ,the ready removal or adjustment of the bits tangular lug 34 of the spring relrauztorz When the retractor is slipped through the Ui recess into the body 2 the lng 34 will register with the slot 35 in the rod l and upon turning the retractor, the lng forcee the rod 4 downward against the tension of the spring 6 by engaging the. lower wall of nl the slot 35. Upon turning the lng 34 to its limit of throw downward the rod 4 is there by locked against the tension of the snring 6 so that bits may be removed or closed in f to permit the toc-.l being inserted into 'the mi well casing, in which latter cese ns soon es the tool has been inserted into the well we ingn snllicieutdistance for the end oi' "the casing, or the shoe thereon, to extend over n. the upper ends of the Shanks of the hits the m' sus retractor is turned to unlock the rod 4 and is withdrawn from the body 2.

In Fig, 15 I have shown the end of the shank 33 slotted for the insertion of an operating key and a bushing 36 for closing the recess 32. It is obvious' that the shank 33 may be provided with an operating head as shown in Fig. 14, or slotted as shown inv Fig. 15, to be operated by a key or may be squared for o eration by a wrench as desired. It is o vious that as an equivalent for thehank 33 and lug 34 I may use a tapered key which may be driven through the body 2 into the recess 35 bearing against -the lower wall thereof and thereby forcing the rod 4 down against the spring until the rod has registered its lower limit. In case such tapered key is used a suitable head would be provided on the tapering key for pulling it out of the tool when desired.

I claim 1 l. The combination of a body or mandrel,

a spring-actuated rod therein, the body having slotted sides, a key way in said rod, a key there-in, hits tiltingly mounted on said key, the lower end of said mandrel being inclined downwardly and inwardly toward the center, said bits provided with shoulders adapted to bear thereon and provided with recesses openin inwardly near the bottom of said mandre abutments projecting outwardly from the slotted sides and near the bottom of the mandrel and extending into the recesses in said bits, the under surfaces of said abutments being downwardly and outwardly inclined and the lower surfaces or walls of said recesses bein correspond ingly inclined `to abut thereagamst when the bits are in expanded position.

2. The combination of a body or mandrel having slotted sides, a spring actuated rod therein havingr a key way near its lower end, a, key therein, bits tiltingly mounted on said key and provided with lateral shoulders, the end of the mandrel being inclined to coact with said shoulderssnd cause the bits to expand, the body of the mandrel provided with a way and the rod with a slot registering therewith and means insertible through said way and into said slot to lock said rod down against the tension of its spring.

3. The combination ofl a body or mandrel, a springHactuated rod therein, the body having slotted sides,` bits or cutters tiltingly mounted on said spring-actuated rod, the upper walls of the slotted-'sides being provided with abutments or surfaces, the lower end of the mandrel being downwardly and inwardly inclined, downwardly and outwardly inclined abutments at the lower end of the slotted portion of said body, said bits provided at their upper endswith inclined portions adapted to coact with said inclined abutments and with recesses fitting over the inclined abutments at the lower end of said slotted portion and having the lower walls of such recesses correspondingly inclined and provided with shoulders adapted to bear against the inclined ends of the inandrel.

The combination of a body or mandrel, a springactuated rod therein, tilt cutters or bits thereon, the body or mandrel at its lower end being inclined downwardly and inwardly, said cutters or bits provided with shoulders adapted to bear thereagainst, downwardly and outwardly inclined abutments on said mandrel, the bits having recesses receiving and adapted to embrace said abutments and provided with surfaces adapted to bear against said abutments when in expanded position.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 15th day .of March, 1912.

THOMAS J. GRIFFIN.

In presence of FREDERICK S. LYON, ELrzABE'rH BLAsDEL. 

